<!DOCTYPE html>
<html prefix="og: http://ogp.me/ns# article: http://ogp.me/ns/article# " lang="en">
<head>
<meta charset="utf-8">
<meta name="description" content="Tj2's Blog">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>绿萝间 (old posts, page 180) | 绿萝间</title>
<link href="assets/css/all-nocdn.css" rel="stylesheet" type="text/css">
<link href="assets/css/ipython.min.css" rel="stylesheet" type="text/css">
<link href="assets/css/nikola_ipython.css" rel="stylesheet" type="text/css">
<meta name="theme-color" content="#5670d4">
<meta name="generator" content="Nikola (getnikola.com)">
<link rel="alternate" type="application/rss+xml" title="RSS" href="rss.xml">
<link rel="canonical" href="https://muxuezi.github.io/index-180.html">
<link rel="prev" href="index-181.html" type="text/html">
<link rel="next" href="index-179.html" type="text/html">
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
    tex2jax: {
        inlineMath: [ ['$','$'], ["\\(","\\)"] ],
        displayMath: [ ['$$','$$'], ["\\[","\\]"] ],
        processEscapes: true
    },
    displayAlign: 'center', // Change this to 'center' to center equations.
    "HTML-CSS": {
        styles: {'.MathJax_Display': {"margin": 0}}
    }
});
</script><!--[if lt IE 9]><script src="assets/js/html5.js"></script><![endif]-->
</head>
<body>
<a href="#content" class="sr-only sr-only-focusable">Skip to main content</a>

<!-- Menubar -->

<nav class="navbar navbar-inverse navbar-static-top"><div class="container">
<!-- This keeps the margins nice -->
        <div class="navbar-header">
            <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-navbar" aria-controls="bs-navbar" aria-expanded="false">
            <span class="sr-only">Toggle navigation</span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            </button>
            <a class="navbar-brand" href="https://muxuezi.github.io/">

                <span id="blog-title">绿萝间</span>
            </a>
        </div>
<!-- /.navbar-header -->
        <div class="collapse navbar-collapse" id="bs-navbar" aria-expanded="false">
            <ul class="nav navbar-nav">
<li>
<a href="archive.html">Archive</a>
                </li>
<li>
<a href="categories/">Tags</a>
                </li>
<li>
<a href="rss.xml">RSS feed</a>

                
            </li>
</ul>
<ul class="nav navbar-nav navbar-right"></ul>
</div>
<!-- /.navbar-collapse -->
    </div>
<!-- /.container -->
</nav><!-- End of Menubar --><div class="container" id="content" role="main">
    <div class="body-content">
        <!--Body content-->
        <div class="row">
            
            

    
<div class="postindex">
    <article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/dlott-15078-2015-07-08-report.html" class="u-url">大乐透15078期(2015-07-08)数据分析报告</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/dlott-15078-2015-07-08-report.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-09T08:00:00+08:00" title="2015-07-09 08:00">2015-07-09 08:00</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div>
<p>如有雷同，纯属巧合</p>
<p class="more"><a href="posts/dlott-15078-2015-07-08-report.html">Read more…</a></p>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/9-from-the-perceptron-to-support-vector-machines.html" class="u-url">9-from-the-perceptron-to-support-vector-machines</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/9-from-the-perceptron-to-support-vector-machines.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-08T09:15:04+08:00" title="2015-07-08 09:15">2015-07-08 09:15</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div tabindex="-1" id="notebook" class="border-box-sizing">
    <div class="container" id="notebook-container">

<div class="cell border-box-sizing text_cell rendered">
<div class="prompt input_prompt">
</div>
<div class="inner_cell">
<div class="text_cell_render border-box-sizing rendered_html">
<h2 id="从感知器到支持向量机">从感知器到支持向量机<a class="anchor-link" href="posts/9-from-the-perceptron-to-support-vector-machines.html#%E4%BB%8E%E6%84%9F%E7%9F%A5%E5%99%A8%E5%88%B0%E6%94%AF%E6%8C%81%E5%90%91%E9%87%8F%E6%9C%BA">¶</a>
</h2>
</div>
</div>
</div>
<div class="cell border-box-sizing text_cell rendered">
<div class="prompt input_prompt">
</div>
<div class="inner_cell">
<div class="text_cell_render border-box-sizing rendered_html">
<p>上一章我们介绍了感知器。作为一种二元分类器，感知器不能有效的解决线性不可分问题。其实在<em>第二章，线性回归</em>里面已经遇到过类似的问题，当时需要解决一个解释变量与响应变量存在非线性关系的问题。为了提高模型的准确率，我们引入了一种特殊的多元线性回归模型，多项式回归。通过对特征进行合理的组合，我们建立了高维特征空间的解释变量与响应变量的线性关系模型。</p>
<p>随着特征空间的维度的不断增多，在用线性模型近似非线性函数时，上述方法似乎依然可行，但是有两个问题不可避免。首先是计算问题，计算映射的特征，操纵高维的向量需要更强大的计算能力。然后是与算法归纳有关的问题，特征空间的维度的不断增多会导致维度灾难。从高维的特征变量中学习，要避免拟合过度，就需要呈指数级增长的训练数据。</p>
<p>这一章，我们将介绍一种强大的分类和回归模型，称为支持向量机（support vector machine，SVM）。首先，我们将学习高维空间的特征映射。然后，我们将介绍，在处理被映射到高维空间的数据时，支持向量机是如何缓解那些计算与综合问题的。有许多书整本整本的介绍SVM，相关的优化算法需要比前面章节里介绍其他算法更多的数学知识。我们不再用前面那些章节的小例子来演示算法，而是通过直观的案例来介绍scikit-learn如何有效的使用SVM去解决问题。</p>
<p class="more"><a href="posts/9-from-the-perceptron-to-support-vector-machines.html">Read more…</a></p>
</div>
</div>
</div>
</div>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/8-the-perceptron.html" class="u-url">8-the-perceptron</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/8-the-perceptron.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-08T09:13:39+08:00" title="2015-07-08 09:13">2015-07-08 09:13</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div tabindex="-1" id="notebook" class="border-box-sizing">
    <div class="container" id="notebook-container">

<div class="cell border-box-sizing text_cell rendered">
<div class="prompt input_prompt">
</div>
<div class="inner_cell">
<div class="text_cell_render border-box-sizing rendered_html">
<h2 id="感知器">感知器<a class="anchor-link" href="posts/8-the-perceptron.html#%E6%84%9F%E7%9F%A5%E5%99%A8">¶</a>
</h2>
</div>
</div>
</div>
<div class="cell border-box-sizing text_cell rendered">
<div class="prompt input_prompt">
</div>
<div class="inner_cell">
<div class="text_cell_render border-box-sizing rendered_html">
<p>前面，我们介绍了广义线性模型，用联接方程描述解释变量、超参数和响应变量的线性关系。这一章，我们将介绍另一种线性模型，称为感知器（perceptron）。感知器是一种研究单个训练样本的二元分类器，训练较大的数据集很有用。而且，感知器和它的不足激发了我们后面两种将介绍的模型。</p>
<p class="more"><a href="posts/8-the-perceptron.html">Read more…</a></p>
</div>
</div>
</div>
</div>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/slott-2015078-2015-07-07-report.html" class="u-url">双色球2015078期(2015-07-07)数据分析报告</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/slott-2015078-2015-07-07-report.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-08T08:00:00+08:00" title="2015-07-08 08:00">2015-07-08 08:00</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div>
<p>如有雷同，纯属巧合</p>
<p class="more"><a href="posts/slott-2015078-2015-07-07-report.html">Read more…</a></p>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/dlott-15077-2015-07-06-report.html" class="u-url">大乐透15077期(2015-07-06)数据分析报告</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/dlott-15077-2015-07-06-report.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-07T08:00:00+08:00" title="2015-07-07 08:00">2015-07-07 08:00</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div>
<p>如有雷同，纯属巧合</p>
<p class="more"><a href="posts/dlott-15077-2015-07-06-report.html">Read more…</a></p>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/slott-2015077-2015-07-05-report.html" class="u-url">双色球2015077期(2015-07-05)数据分析报告</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/slott-2015077-2015-07-05-report.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-06T08:00:00+08:00" title="2015-07-06 08:00">2015-07-06 08:00</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div>
<p>如有雷同，纯属巧合</p>
<p class="more"><a href="posts/slott-2015077-2015-07-05-report.html">Read more…</a></p>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/dlott-15076-2015-07-04-report.html" class="u-url">大乐透15076期(2015-07-04)数据分析报告</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/dlott-15076-2015-07-04-report.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-05T08:00:00+08:00" title="2015-07-05 08:00">2015-07-05 08:00</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div>
<p>如有雷同，纯属巧合</p>
<p class="more"><a href="posts/dlott-15076-2015-07-04-report.html">Read more…</a></p>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/slott-2015076-2015-07-02-report.html" class="u-url">双色球2015076期(2015-07-02)数据分析报告</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/slott-2015076-2015-07-02-report.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-03T08:00:00+08:00" title="2015-07-03 08:00">2015-07-03 08:00</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div>
<p>如有雷同，纯属巧合</p>
<p class="more"><a href="posts/slott-2015076-2015-07-02-report.html">Read more…</a></p>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/7-dimensionality-reduction-with-pca.html" class="u-url">7-dimensionality-reduction-with-pca</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/7-dimensionality-reduction-with-pca.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-02T09:38:42+08:00" title="2015-07-02 09:38">2015-07-02 09:38</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div tabindex="-1" id="notebook" class="border-box-sizing">
    <div class="container" id="notebook-container">

<div class="cell border-box-sizing text_cell rendered">
<div class="prompt input_prompt">
</div>
<div class="inner_cell">
<div class="text_cell_render border-box-sizing rendered_html">
<h2 id="用PCA降维">用PCA降维<a class="anchor-link" href="posts/7-dimensionality-reduction-with-pca.html#%E7%94%A8PCA%E9%99%8D%E7%BB%B4">¶</a>
</h2>
</div>
</div>
</div>
<div class="cell border-box-sizing text_cell rendered">
<div class="prompt input_prompt">
</div>
<div class="inner_cell">
<div class="text_cell_render border-box-sizing rendered_html">
<p>本章我们将介绍一种降维方法，PCA（Principal Component Analysis，主成分分析）。降维致力于解决三类问题。第一，降维可以缓解维度灾难问题。第二，降维可以在压缩数据的同时让信息损失最小化。第三，理解几百个维度的数据结构很困难，两三个维度的数据通过可视化更容易理解。下面，我们用PCA将一个高维数据降成二维，方便可视化，之后，我们建一个脸部识别系统。</p>
<p class="more"><a href="posts/7-dimensionality-reduction-with-pca.html">Read more…</a></p>
</div>
</div>
</div>
</div>
</div>
    </div>
    </article><article class="h-entry post-text"><header><h1 class="p-name entry-title"><a href="posts/dlott-15075-2015-07-01-report.html" class="u-url">大乐透15075期(2015-07-01)数据分析报告</a></h1>
        <div class="metadata">
            <p class="byline author vcard"><span class="byline-name fn">
                Tao Junjie
            </span></p>
            <p class="dateline"><a href="posts/dlott-15075-2015-07-01-report.html" rel="bookmark"><time class="published dt-published" datetime="2015-07-02T08:00:00+08:00" title="2015-07-02 08:00">2015-07-02 08:00</time></a></p>
        </div>
    </header><div class="p-summary entry-summary">
    <div>
<p>如有雷同，纯属巧合</p>
<p class="more"><a href="posts/dlott-15075-2015-07-01-report.html">Read more…</a></p>
</div>
    </div>
    </article>
</div>

        <nav class="postindexpager"><ul class="pager">
<li class="previous">
                <a href="index-181.html" rel="prev">Newer posts</a>
            </li>
            <li class="next">
                <a href="index-179.html" rel="next">Older posts</a>
            </li>
        </ul></nav><script type="text/javascript" src="https://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"> </script><script type="text/x-mathjax-config">
MathJax.Hub.Config({
    tex2jax: {
        inlineMath: [ ['$','$'], ["\\(","\\)"] ],
        displayMath: [ ['$$','$$'], ["\\[","\\]"] ],
        processEscapes: true
    },
    displayAlign: 'center', // Change this to 'center' to center equations.
    "HTML-CSS": {
        styles: {'.MathJax_Display': {"margin": 0}}
    }
});
</script>
</div>
        <!--End of body content-->

        <footer id="footer">
            Contents © 2017         <a href="mailto:muxuezi@gmail.com">Tao Junjie</a> - Powered by         <a href="https://getnikola.com" rel="nofollow">Nikola</a>         
<a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0">
<img alt="Creative Commons License BY-NC-SA" style="border-width:0; margin-bottom:12px;" src="http://i.creativecommons.org/l/by-nc-sa/4.0/80x15.png"></a>
            
        </footer>
</div>
</div>


            <script src="assets/js/all-nocdn.js"></script><script>$('a.image-reference:not(.islink) img:not(.islink)').parent().colorbox({rel:"gal",maxWidth:"100%",maxHeight:"100%",scalePhotos:true});</script><!-- fancy dates --><script>
    moment.locale("en");
    fancydates(0, "YYYY-MM-DD HH:mm");
    </script><!-- end fancy dates --><script>
  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
  (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
  m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
  })(window,document,'script','//www.google-analytics.com/analytics.js','ga');

  ga('create', 'UA-51330059-1', 'auto');
  ga('send', 'pageview');

</script>
</body>
</html>
